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  1. hevans1944

    Safe sequencing of power

    Huh? Go look at the reply again. @haqq clearly stated he wanted to switch a 30 kW load on and off and asked how to do that. The moderator just as clearly stated this was a job for a licensed electrician, not suitable for a hobbyist forum, and closed the thread. I wholeheartedly agree with that...
  2. hevans1944

    Volts to ohms for fuel sender

    And now i wonder why no one has mounted motorcycle fuel tanks on miniature load cells. This arrangement would not be sensitive to volume variations as a function of depth, as float-based or ultrasonic-based transducers are. Measuring the weight of the fuel remaining in the tank is a more...
  3. hevans1944

    Safe sequencing of power

    Which is why I suggested the person plugging in the products, running up and down the line to turn them on and off, and swapping them out with new ones to test, was probably an intern or apprentice. Not directly applying that to @haqq, but if the shoe fits... And if it does fit, maybe he or she...
  4. hevans1944

    HELP! Wireless Keyfinder Project

    China of course. Maybe other countries in that region of the world. You charge more than $111 per hour for your services?! Yikes, no wonder you are a VIP Member! Maybe Ian should change that to VWVIP or VVIP.:D
  5. hevans1944

    Safe sequencing of power

    I am thinking a PIC driving a 32-bit shift register, each bit available for output to drive each of the 32 power switches. When it is first turned on, all the bits are cleared. Then when the START button is pressed the PIC presents a logic 1 to the input of the shift register, issues a clock...
  6. hevans1944

    Volts to ohms for fuel sender

    I did consider it, and @Alec_t's post#13 (LM3914 bar-graph driver) too. It is quite likely that the commercial fuel gauge, which does display fuel levels on an LED bar-graph, uses an LM3914 to perform its function. I was under the misinformed impression that the fuel-gauge was an analog meter...
  7. hevans1944

    Volts to ohms for fuel sender

    I must be getting old, and afflicted wit alt timers disease ta boot. I completely forgot about bar-graph drivers, Colin!
  8. hevans1944

    HELP! Wireless Keyfinder Project

    Did you find one that reports back its GPS co-ordinates to your smartphone for ten bucks? I would be interested. Also interested in a key fob that tells me where I left my smartphone.
  9. hevans1944

    What the Beeeep...

    I would be envious, except I have a "lifetime" supply of solder now: several one pound spools of various diameter solder, all either 60/40 or eutectic 63/47. I even have a spool of 50/50 plumbing solder for sweat soldering copper plumbing, but I don't use that for water plumbing. It's for...
  10. hevans1944

    Volts to ohms for fuel sender

    We could get that to work (probably) but it is a little short on output ports if you use the A/D functionality. Would need some support or glue circuits. And the OP already has an Arduino he wants to use. Need one analog input and eight digital outputs with no glue circuitry, but maybe some reed...
  11. hevans1944

    Volts to ohms for fuel sender

    WOW! POC now. You can use your panel readout at whatever the default sensitivity is (240-33 or 73-10) without custom programming. Just go to Radio Shack or the Australian equivalent and buy a couple of cheap 100 ohm potentiometers because you are gonna do a test. Using just ONE of the two pots...
  12. hevans1944

    Safe sequencing of power

    A recent newby poster, @haqq, asked: I have a product testing line with 30 products (1KW each) plugged in at the same time and after completion of the test, all these items are plugged off at the same time. I need to automate this process i.e: Turn on all the 30 items at the same time turn off...
  13. hevans1944

    Underwater Wireless Communication

    What part of "will not work underwater" do you not understand? The buoy is above water and presumably tethered to the bottom under whatever water it is in, so it won't just float away. Take advantage of this. Tie your transducer box to the buoy cable with plastic tie-wraps, run a jacketed...
  14. hevans1944

    What the Beeeep...

    Okay, tin/lead solder appears to be a little pricey in Europe, but a real bargain in Australia at AU$68 per kilogram. Hmm. Wonder if @davenn meant English pounds instead of metric kilograms? Anyhoo, Europe hates lead so much that may account for the price. They don't want you to use solder that...
  15. hevans1944

    Help optimizing byte compare algorithm

    I never much enjoyed playing around with assembly for DEC PDP-11 computers. Back then, BASIC or FORTRAN-77 was more my speed. I did love to program Intel 8085 microprocessors in assembly, but only because I am a hardware guy and the software folks where I worked turned their noses up at...
  16. hevans1944

    Help optimizing byte compare algorithm

    @chopnhack would know more about that than I. He uses a C compiler with his PICs. I have discouraged him from doing this, but to no avail. The C compiler does encourage the use of proper programming techniques. Not a GOTO in sight with C. Plenty of IF, THEN, ELSE and CASE statements sprinkled...
  17. hevans1944

    What is L70?

    When sales interfaces with a customer, the proper response is always, "Absolutely!" Get the cash and let Customer Service handle the after-sale details. For the typing challenged, try this.
  18. hevans1944

    Help optimizing byte compare algorithm

    Yeah, the PIC goto command is used extensively for loop iteration because it does not have a JZ or JNZ instruction. The use of tests that skip the next instruction if the test is successful requires a jump (goto) instruction as the next instruction to make sure the loop iterates when the test...
  19. hevans1944

    Volts to ohms for fuel sender

    That's exactly what I thought when I suggested the MOSFET-switched resistor network to @Calabashmc, although I was thinking along the lines of the classic R-2R constant input-resistance ladder network that diverts currents in a binary fashion. So, instead of that scheme (which won't work) we...
  20. hevans1944

    HELP! Wireless Keyfinder Project

    You get points in a science fair by presenting a unique way of looking at something. The judges are looking for creativity and understanding. A key fob locator would likely be a winner if you incorporated a GPS receiver in the fob and interrogated it with a Bluetooth transciever in the fob...
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